Both EP 98402916.5 and EP 01402614.0 provide for the mounting of the solenoid valve on the cartridge by means of an adapter. The adapter is designed to receive the two ends of the cartridge and of the solenoid valve, to both of which pressure has to be applied in order to allow for the transfer of gas from the cartridge to the solenoid valve, as well as a seal between the two.
Problems of two kinds may arise with either of the arrangements of the two documents mentioned hereinabove.
The seal may expand and become jammed on the outlet end of the cartridge. In this case, if the cartridge is removed when it is not yet empty, the gas will escape. It will be noted that, when the cartridge is not empty, it is quite easy to remove the cartridge by virtue of the temporary escape of the gas, which ejects it from its housing.
However, when the cartridge is empty, it may be difficult to grip it by its base and remove it from its housing.
Adapting the solenoid valve to a gas cartridge moreover involves a lot of components. Even if the dimensions of each of these components comply with the high tolerance limits, taken as a whole, problems may arise with mounting. Thus, if an annular groove is provided on the cartridge adapter, intended to receive locking means, as instructed by EP 01402614.0, correct mounting of the cartridge in its housing with locking of the adapter may be rendered impossible, with the cartridge not being held in its housing.
Conversely, the cartridge may be placed in its housing, but the series of dimensions is such that it is impossible to slide the end of the cartridge sufficiently for the gas to escape as the impact stroke is insufficient.